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Struggling with the nine times table? I have a failsafe method (www.theguardian.com)
submitted 3 months ago by to c/nottheonion@lemmy.world
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Apparently, nines are the hardest to grasp for primary school children. If only they’d learned how to cheat like me, says Adrian Chiles

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[–] 2 points 3 months ago* (last edited 3 months ago) (1 child)

I agree the the number-theoretic shortcuts for multiplication (and division!) based on the factors of 9, 10, and 11 should be taught.

I disagree that single-digit sums and products shouldn't be memorized. Neither students nor practitioners derive formulae from first principles each and every time, and breaking down a single-digit sum or product into "simpler" ones is a very similar ask.

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  • [–] 3 points 3 months ago

    Neither students nor practitioners derive formulae from first principles each and every time,

    1. If they have it memorized, it's from years of usage, they didn't need to practice moroizing the things theyd use every day. Because it would happen anyways.

    2. Math class isn't applied Math, it's just Math. Giving credit for memorizing someone else's equation is a way to push people thru who can't do the math.

    And even in a hypothetical world where someone needs to apply an existing mathematical formula that they don't use constantly, they're not gonna just risk it to save 2 seconds checking.

    I understand why you have the opinion you have, but that doesn't mean our education system was blinded in the pursuit of metrics generations ago, hell, it's ancedotal evidence it did...

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